I fired a garand qualification match in Yucca Valley along with 3 other fellow law enforcement officers in the late 1970's at 100 yards using 600 yard simulator targets.One of the participants was using his 30-06 mil 1903 Springfield rifle for slow & rapid fire standing kneeling & prone but he put most of his shots in the 10 ring and a few in the 9 ring,we watched in awe as this eldery shooter performed.His shooting coat had 2 emblems 1950 & 1951 USA National High Power Rifle Champion,he told us he had fired in excess of 58,000 rounds in practice and competition thru his rifle and it only had approx 6 inches of rifling left near the muzzle.I've read so many articles about barrel life from people who have never duplicated the master riflemans fete we watched that afternoon with a 'shot out barrel' that was still deadly accurate.